ALOE BARBADENSIS LEAF JUICE
(ALOE VERA GEL):
A PRIMER
ALOE BARBADENSIS LEAF JUICE: A PRIMER
SOURCES OF ALOE VERA GEL (ALOE BARBADENSIS LEAF JUICE)
Aloe Barbadensis Leaf Juice, more commonly known as aloe vera gel, is the liquid (or its dehydrated solids)
from the leaf of the Aloe barbadensis plant. The juice from the mucilaginous inner fillet has traditionally been
used in cosmetic and nutritional (drink) applications, as it is light in color, bland in taste (i.e., free of the bitter
aloin that is present in the outer, green portion of the leaf) and rich in carbohydrates, trace minerals and
various organic substances that promote hydration of the skin and health of the body. Whole leaf aloe, which
has gained some popularity more recently, makes use of the juice obtained by macerating the entire leaf and
collecting and filtering the juice obtained therefore. Whole leaf aloe typically starts with a greenish hue that
turns dark brown upon aging. Frequently, it is processed to limit aloin content. Regardless, as would be
expected, the compositions and solids contents of these two types of aloe juices vary markedly.
PROCESSING OF ALOE VERA GEL
Traditional, inner fillet, aloe vera gel is prepared within 24 hours of harvest. The firm, translucent, pale yellow,
slimy inner portion of the leaf (the “inner fillet”) is removed by hand from the leaf and macerated, releasing the
juice from its complex carbohydrate matrix. The macerate is then filtered to remove insoluble material. At
this point, product may be decolorized and/or concentrated and, if still in liquid form, preservative is added to
prevent microbial growth. Just as orange juice is often sold as a concentrate, so is aloe vera gel. The most
common extents of concentration are ten-fold and forty-fold (both liquids) and two hundred-fold (a solid).
Whole leaf aloe vera gel is prepared by macerating the entire leaf, which yields about twice the solids content
of inner leaf aloe vera gel. As a result, the most common concentrates are five-fold, twenty-fold (both liquids)
and one hundred-fold a solid). In addition to the filtration, concentration, and preservation steps, the juice
may be handled and/or treated in such a way as to limit aloin content.
CONCENTRATION OF ALOE VERA GELS
A key to understanding how much aloe barbadensis leaf juice is in a product is knowing how much
nonvolatile material is present in the macerated filtered aloe leaves. While the value varies somewhat
depending on the plant subspecies used, plant age and the prevailing climatic and other environmental
conditions, inner fillet aloe barbadensis leaf juice is typically about 99.5% water. So a ten-fold concentrated
inner leaf aloe vera gel will have about 5% solids and is commonly called a 10X product. Similarly, a fortyfold concentrated product is about 20% solids and is called a 40X product, and an essentially completely
dehydrated (powdered) product is about two hundred fold concentrated and called a 200X product.
Because whole leaf aloe barbadensis leaf juice is typically about 99.0% water, five-fold concentrated inner
leaf aloe vera gel will have about 5% solids and is commonly called a 5X product. Similarly, a twenty-fold
concentrated product is about 20% solids and is called a 20X product, and an essentially completely
dehydrated (powdered) product is about one hundred-fold concentrated and called a 100X product.
CHANGING GRADES OF ALOE VERA GEL IN A PRODUCT
Between whole leaf and inner fillet
Whole leaf products are a different shade and darker in color at the same concentration than inner leaf
products. Further, they darken more with time. So conversion from inner fillet to whole leaf aloe, even at an
equal solids level, presents a significant discoloration risk, initially and long term, which requires stability
testing. The higher the aloe concentration in the finished product, the greater the concern. If used at a
relatively high level in the finished product (percents, vs. tenths of a percent), an assessment of
microbiological, ionic and pH effects of the change should also be made (see below).
Between freeze-dried powder and spray-dried powder
Truly freeze-dried powders, immediately after reconstituting in water, will have the slimy feel of aloe vera gel
freshly expressed from the aloe vera leaf. The slimy feel is preserved until reconstitution because the cold
processing temperature limits the activity of enzymes in the aloe vera gel that clip polysaccharide chains,
resulting in loss of the slimy feel. The effect of chain length can be illustrated by comparing the feel of very
high molecular weight polyethylene glycols (such as PEG-60M) with lower molecular weight versions (such
as PEG-12). The very high molecular weight is required for the slimy feel. There is little value in paying more
for freeze-dried aloe that is reconstituted prior to end use by the consumer, because as soon as aloe vera gel
is dissolved in room temperature water, the enzymes go to work and clip the polysaccharides. Very high
molecular weight polysaccharide will no longer remain by the time the consumer uses the finished product.
Between different grades of powders
Maltodextrin, obtained from partially hydrolyzed starch, has been the product of choice to improve the spray
drying characteristics of aloe vera gel. Unfortunately, because it is a carbohydrate somewhat similar to the
majority of the composition of aloe vera gel, but much less costly, it has been used to increase the amount of
“aloe vera gel” powder yielded in the spray drying process. Some suppliers set their price for aloe vera gel
powders in direct proportion to the amount of actual aloe vera gel solids in the product (low true aloe vera
solids, low price). HallStar’s CoVera ™ Dry and CoVera ™ ETD are made with a bare minimum of
maltodextrin. It is truly used as a processing aid, not as an extender. The primary disadvantage of a high
maltodextrin content aloe vera gel is the reduction in the levels of trace minerals and many non-carbohydrate
organic substances present in true aloe vera gel solids. The varying complex carbohydrate fraction may also
affect the moisturization and hydration benefits of finished products.
Between different concentrations of the same grade (inner fillet or whole leaf)
Virtually all liquid forms of aloe vera gel are preserved using either a food grade or cosmetic grade
preservative system. The food grade preservative systems typically include one or more of Methylparaben,
Benzoic Acid, Sodium Benzoate, Sorbic Acid, Potassium Sorbate, Citric Acid and/or other FCC (Food
Chemicals Codex/food grade) preservatives. Cosmetic grade preservative systems typically include a
formaldehyde donor, which may be supplemented by parabens.
When the amount of aloe in the product is substantial (perhaps 5% or more of the finished formulation), it is
adding substantially to the overall preservative system. Going from a more concentrated to less concentrated
aloe vera gel with the same preservative system yields more preservative in the finished product, and so no
microbiological problems are anticipated. But going from a more dilute to a more concentrated aloe vera gel
CAN produce a microbiological problem, because the preservative system is being weakened since there is
less total preservative present.
This is particularly true when going form a liquid product to a powder, because many aloe vera gel powders
have no added preservative at all; they are sealed and irradiated to ensure sterility at the time of opening of
the package. So if the entire contents of the package are not used at once and moisture gets in the product,
the aloe vera gel can become a breeding ground for microorganisms. For this reason, The HallStar Company
has aloe vera powders (CoVera ™ Dry and CoVera ™ ETD) in package sizes defined by our customers,
allowing the entire contents to be used at once. The bottom line is that either challenge testing of the new
formula is required or, for greater security, the lost preservatives should be added separately to the system to
maintain the original levels.
Beyond the preservative issue, there are also potential concerns related to ionic strength and pH. Food
grade aloe vera gel liquids typically utilize ionic preservatives such as Potassium Sorbate and/or Sodium
Benzoate with an acid such as Sorbic Acid, Benzoic Acid or Citric Acid to maintain the somewhat acidic pH
necessary for good preservative efficacy. Aloe vera gel powders and cosmetic grade liquids typically do not
use ionic preservatives and are essentially unbuffered and near neutral pH. As a result, switching between
food grade aloe liquids and food or cosmetic grade powders or cosmetic grade liquids may result in changes
in finished product pH, rheology and/or emulsion stability. Consequently, initial product evaluation and
extended stability testing should be performed on the modified formula to ensure that any changes in ionic
strength and/or pH are inconsequential.
SO HOW DO I SAFETY CHANGE THE ALOE IN MY FINISHED PRODUCTS?
Contact your sales representative and request an evaluation of the benefits of a proposed change. Given
your current Aloe Vera Gel strength, composition and cost, we can provide you an apples to apples
comparison of your current aloe vera gel with various HallStar CoVera ™ products, including any cost to
incorporate additional preservatives and/or buffering acids towards maintaining product integrity. The
decision as to whether to act on any recommendations remains yours. We’d appreciate the opportunity to be
of assistance.
CoVeraAloeVeraGelPrimer
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regarding the information or the performance of any product. Further, nothing contained herein shall be taken as any inducement or
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